GB2206494A

GB2206494A - An orthosis or prosthesis for coordinating limb movement

Info

Publication number: GB2206494A
Application number: GB08814913A
Authority: GB
Inventors: David Hart
Original assignee: Hugh Steeper Ltd
Current assignee: Hugh Steeper Ltd
Priority date: 1987-06-24
Filing date: 1988-06-23
Publication date: 1989-01-11
Anticipated expiration: 2008-06-23
Also published as: GB8814913D0; US4946156A; JP2787313B2; DE3821409A1; FR2617041B1; JPH0197456A; FR2617041A1; GB2206494B; DE3821409C2

Description

2 L U 6 4 u,' 4 Orthoses or Prostheses for coordinating limb movement The

present invention, in some aspects, relates to prostheses or orthoses for assisting limb movement in a paraplegic person or in a person with a disabled or missing limb. The present invention also relates, in another aspect, to a device useful in such an orthosis or prosthesis.

one aspect of the present invention relates to a reciprocating gait orthosis.

The Louisiana State University Reciprocating Gai Orthosis (LSURGO), as known, comprises means which couple a left and a right leg brace together in such a way that hip f lexion in either one tends to force the other hip joint into extension, thereby providing a co- ordinating motion of the legs making possible a reciprocating galt. Each leg brace includes a pivotal joint at the hip, and the two hip joints are coupled by two cables.

An interconnected limb arrangement having two artificial limbs interconnected by two cables to coordinate the movement of the limbs is also known from GB-A-1188647 (Hartley).

Whilst the LSURGO works well, the use of two cables makes for complication in the manufacture of the orthosis.

According to one aspect of the present invention, there is provided a reciprocating gait orthosis wherein the hip joints are coupled by a single push/pull member.

Another aspect of the present invention comprises a push/pull member in the form of an inner cable and two tubes, one within the other, which all move together. Such a member is used in a preferred embodiment of the 5 reciprocating gate orthosis.

A further aspect of the present invention rela tes to an orthosis or prosthesis which co-ordinates, and assists, movement between two parts of the same limb. The further aspect relates for example to assisting the paraplegic or disabled person in moving between sitting and standing postures.

Many different arrangements are known which include a spring or other elastic or resilient device associated with an artificial knee joint to assist straightening of an artificial leg, or to assist in straightening the leg of a disabled person, but the known arrangements operate only on or across the single knee joint. Examples of such arrangements include GB-A- 2004753 (Blatchford) and GB-A- 813501 (Cresswell).

According to the further aspect of the present invention, there is provided an orthosis or prosthesis for coordinating movement about two joints of the same limb, comprising a limb member having pivotal joints at respective ends thereof joining the limb member to further members, a coordination member pivotally coupled to the further members for coordinating rotation of one of the further members about one of the joints with rotation of the other of the further members about the other joint, and resilient means which urges the orthosis or prosthesis into a particular configuration.

For a better understanding of the present invention, reference will now be made by way of example to the accompanying drawings, in which:- Figure 1 is a perspective view of an illustrative orthosis according to the invention fitted to a paraplegic patient; Figures 2 to 16 are perspective, side, front and sectional views through different parts of the orthosis; Figure 17 is a side view of a modification of the orthosis shown in Figures 1 to 16; and Figures 18 to 24 show a modification of what is shown in Figure 17.

The illustrated reciprocating gait orthosis of Figure 1 comprises left and right leg braces which include lower steels 10 - see Figures 8 to 10 - and upper steels 12- see Figures 5 to 7 - each of which are provided with respective eyelets 14, 16 through which a hub 18 passessee Figure 16 - so that the upper and lower steels are pivoted together. The hub is internally screw-threaded at 20 so as to receive a screw-threaded bush or bearing screw 22 - see Figure 15. The hub 18 passes through roller thrust races 21 in the steel 10 which bear outwardly against a hardened steel bush and the head of the screw 22 and inwardly against hardened steel washers 25.

Each hub 18 and its respective bearing screw 22 together form a hip joint pivotally connecting the upper and lower steels. The two hip joints are arranged one on each side of the patient. The two lower steels are coupled together by a single push/pull member 28, one end of which is best shown in Figure 11, the other end being identical. The push/pull member 28 moves with clearance within a tubular steel carrier 36 fixed to a back band 38. Each lower steel 10 can be uncoupled from the push/pull member and thus from the other lower steel by a locking plunger 24 and catchplate 46 - see Figures 12 to 14. As will be seen from Figure 4, this locking plunger is loaded by a spring 26. The spring 26 urges the plunger upwardly into a recess 44 in a catch plate 46: -see Figures 12 and 13. The catch plate 46 is interposed between the steels around the bush 23. The plate 46 has a head 47 which bears against an inclined end surface of the steel 10 when the plunger locks the steel to the plate. When unlocked, the plate 46 can rotate anticlockwise (as viewed in Figure 2) with respect to the lower steel 10.

The push/pull member comprises an inner metal cable 30 which is surrounded by two nylon tubes 32 and 34. The outer nylon tube 34 is a tight fit on the inner nylon tube 32, and the inner nylon tube closely embraces the metal l inner cable 30 so that they can all move together.

The cable has a ferrule 40 at its end. Between the ferrule and the inner tube 32 is an externally threaded metal tube 39 through which the cable passes. The metal tube extends into the outer tube and an adjusting nut 37 threaded on the metal tube bears against the end of the outer tube 34 to take any play out of the outer tube. A ball joint 42 is threaded onto the tube 39. The ball joint is also attached to the upper end of the lower steel 10 - see Figures 3 and 4. It thus follows that a walking movement of one leg brace causes the other leg brace to move in the opposite direction due to their connection by the push/pull member 28.

It will thus be seen that the reciprocating gait orthosis illustrated in Figures 1 to 16 is of comparatively simple construction which means that it is easier and cheaper to produce and does not give rise to problems in use by the patient.

Fi gure 17 shows an illustrative "up-and-down" orthosis or prosthesis which assists a paraplegic patient or one with a disabled or missing limb, hand or foot to sit down from a standing posture and to rise from a sitting posture. The orthosis of Figure 17 is shown, illustratively, as a modification of the reciprocating gait orthosis of Figures 1 to 16. It will be appreciated, however, that it is inventive in its own right, the concept embodied in the orthosis of Figure 17 being applicable more generally than in just a reciprocating gait orthosis.

The orthosis shown in Figure 17 comprises the upper steel 12, the lower steel 10 and a lower leg steel 19 similar to those shown in Figure 1. The upper and lower steels 12,10 are pivotally coupled by a hip joint as shown in Figures 2 to 4 except for a modif ication to the catch plate 46 which in Figure 17 has an extension or top lever 101 which is either formed on or attached to the catch plate 46. The lower leg steel 19 is coupled to the lower steel 10 by a knee joint 142.

Pivotally connected at 201 to the outer extremity of the top lever 101 and depending therefrom is a hip-to-knee tie rod 121 which has its lower end pivotally connected at 221 to a lower plate 121 which can be f ormed on or be attached to the lower leg steel 19 below the knee joint 142 of the orthosis. Pivotally connected to the lower plate 141 at 241 is a rod 25 which extends into a spring housing 161 and which has an adjusting nut 281 at its inner end to adjust the compression of a helically-coiled spring 301. The upper end of the spring housing 161 is pivotally connected to the lower steel 10 of the orthosis at 321.

The hip joint, lower steel 10, knee joint 142, lower plate 141, top lever 101 and the tie rod 121 pivotally connected to plate 141 and lever 101 form a parallelogram arrangement which coordinates movement about the hip joint with movement about the knee joint. The spring 301 acts to hold the parallelogram in the position corresponding to 5 the standing position of the user.

When a user wishes to sit, the plunger 24 is moved to release the lower steel 10 from the catch plate. The catch plate can then rotate relative to the lower steel about the hip joint. The tie rod 121 then pulls upwardly on the lower plate 141 rotating the knee joint and compressing the spring 301. Thus assistance is given to a patient in sitting down from a standing posture in that the spring controls the patients descent. The spring thus also assists in rising up from a sitting posture.

is The spring 301 and its housing 161 can take many dif f erent f orms. It could, f or example, be replaced by elastic or by a tension spring arranged above the nut 28. A compression spring is, however, saf er. The spring and its housing could be positioned in the parallelogram in positions other than the one shown in Figure 17.

The construction shown in Figure 17 eliminates the need for a knee lock when standing because the lock 24 between the catch plate and the lower steel, together with rod 121, locks the knee.

Figures 18 to 24 show a modification of the orthosis shown in Figure 17.

In the orthosis of Figures 18 to 24 the tie rod 121 takes the form of, or is replaced by, a Bowden cable 342 or the like and a catch 282,382,402 is provided to hold the relatively movable parts 10,19 of the orthosis or prosthesis in two or more specific positions.

The orthosis illustrated in Figure 18 comprises the lower steel 10, the lower leg steel 19 and the knee joint 142 by which the lower and lower leg steels 10, 19 can pivot with respect to each other.

The spring 301 and its housing 161 are in the form of a telescopic assembly 18 pivotally connected at its lower end 241 to the lower plate 141 and is provided with a ball joint connection 222 at its upper end with a projection 242 on the lower steel 10. The coiled compression spring 301 within the telescopic assembly 18 serves to urge the knee joint 142 into a position where the lower leg steel 19 is substantially in alignment with the lower steel 10.

In Figure 18, the lower plate is an integral part of the knee joint 142.

A catch lever 282 is pivotally mounted at 302 on the lower plate 141 and is provided at its outer end 322 with a pivotal connection for the Bowden cable 342. The inner end of the lever 282 is in the form of a nose 362 which engages oppositely facing, spaced apart, first and second shoulders 382 and 402 formed on the lower end of the lower steel 10. Disengagement of the catch nose 362 from the 11 1 - 9 1 > 25 first shoulder 382 allows the lower leg steel 19 to move angularly about the knee joint 142 with respect to the upper steel 10.

The second shoulder 402 on the lower end of the upper steel 10 can likewise be engaged by the catch nose 36.

Such engagement takes place when the lower leg steel 19 has moved to a position where it is approximately at right angles to the lower steel 10. This corresponds to a sitting posture of the person using the orthosis.

10. A spring-loaded ball 422 acts on one end of the catch lever 282 in such a way as to urge the catch nose upwards into engagement with the shoulders.

The upper end of the cable 342 is attached to the top lever 101 of the catch plate 46.

When the user wishes to sit, from a standing position, the catch plate 46 is released from the lower steel 10 as described above. Rotation of the catch plate by the user, then pulls on the cable 342 releasing the catch lever 282 from shoulder 382 and also assisting rotation of the lower leg steel 19 about the knee joint 142 against the spring 301 which thus controls the user's descent. The lever engages the shoulder 402 and prevents the spring from straightening the leg. When standing from a sitting position the user moves to pull on the cable 342 to release the lever 282 from shoulder 402 and so, the spring assists the ascent. The cable 342 coordinates movement about the hip joint with movement about the knee joint.

Figures 19 to 24 show details of the orthosis: it will be noted from Figure 22 in particular that the knee joint 142 at the lower end of the lower steel 10 includes roller thrust bearings 442 and a radial roller bearing 462. Such a joint may be used in the orthosis of Figure 17.

Although the invention has been illustrated by reference to an orthosis, it may be applied also to a prosthesis.

Claims

1. An orthosis or prosthesis for coordinating movement about two joints of the same limb, comprising a limb member having pivotal joints at respective ends thereof joining the limb member to further members, a coordination member coupled to the further members for coordinating rotation of one of the further members about one of the joints with rotation of the other of the further members about the other joint, and resilient means which urges the 10 orthosis or prosthesis into a particular configuration.

2. An orthosis or prosthesis according to claim 1, wherein the further members comprise levers pivotable about the respective joints, and the coordination member is pivotably coupled to the levers remote from the joints.

3. An orthosis or prosthesis according to claim 2, wherein the resilient means connects one of the levers to the limb member.

4. An orthosis or prosthesis according,to claim 1, 2 or 3 comprising means for releasably fixing one of the said 20 further members with respect to the limb member.

5. An orthosis or prosthesis according to anyone of claims 1 to 4 wherein the coordination member is a tie rod.

6. An orthosis or prosthesis according to any one of 25 claims 1 to 4 wherein the coordination member comprises a cable.

7. An orthosis or prosthesis according to claim 6 wherein the coordination member is coupled to the said one of the levers by a further lever which is releasably engageable with the joint associated therewith to lock the joint.

8. An orthosis or prosthesis according to any one of claims 1 to 7 wherein the force exerted by the resilient means on the orthosis or prosthesis is adjustable.

9. An orthosis or prosthesis according to anyone of claims 1 to 8 constructed as a gait orthosis or artificial leg wherein the said joints are hip and knee joints.

10. An orthosis or prosthesis according to claim 9 comprising a locking means for releasably locking the further member associated with the hip joint to the limb member.

11. A reciprocating gait orthosis or prosthesis comprising two orthoses or prostheses according to claim 9 or 10 coupled by means which cause one of the orthoses or prostheses to move in a manner complementary to the other.

12. A reciprocating gait orthosis or prosthesis wherein the hip joints are coupled by a single push/pull member.

13. An orthosis or prosthesis according to claim 12 25 wherein the push/pull member takes the form of an inner metal cable, and two tubes one within the other, which all R 1 25 move together.

14. An orthosis or prosthesis according to claim 13, in which the tubes are of nylon.

15. An orthosis or prosthesis according to claim 13 or 14 wherein the push/pull member is slidably arranged within a tubular guide.

16. An orthosis or prosthesis according to claim 14 or 15, in which the outer tube is a tight f it on the inner tube, while the inner tube closely embraces the inner metal cable.

17. An orthosis or prosthesis according to any one of claims 12 to 17 comprising left and right leg members each leg member having at its upper end a hip joint rotatably coupling the leg membe r to a hip member, the push/pull member coupling the left and right leg members together.

18. An orthosis or prosthesis according to claim 17, wherein the push/pull member is coupled to each leg member by a releasable coupling means.

19. An orthosis or prosthesis according to claim 18, 20 wherein each releasable coupling means comprises a member pivotable about its associated hip joint and connected to the push/pull member, and a means for releasably locking the leg member to the pivotable member.

20. An orthosis or prosthesis according to claim 17, 18 or 19 wherein the push/pull member is connected to ball joint attached to the upper ends of the respective leg members.

21. A push/pull member comprising an inner cable, and two tubes one within the other, which all move together.

22. A member according to claim 21, wherein the tubes are 5 of nylon.

23. A member according to claim 21 or 22, wherein the outer tube is a tight fit on the inner tube, and the inner tube closely embraces the cable.

24. A member according to claim 21, 22 or 23 moveably 10 arranged within a tubular guide.

25. A reciprocating gait orthosis substantially as herein before described with reference to Figures 1 to 16 optically as modified by Figure 17 or by Figures 18 to 24.

26. A push/pull member substantially as hereinbefore described with reference to Figure 11.

27. An orthosis or prosthesis for coordinating movement of a limb substantially as hereinbefore described with reference to Figure 17 or to Figures 18 to 24.

1 QRR at The Patenz Mie. Statc House. 6671 High Ho'born, London WC1R 4TP. Further copies may be obtained from The Patent Office, v f